Jib crane



March 1952 E. G. HUMPAL ETAL JIB CRANE Filed May 19, 1949 5 Sheets-Sheetl INVENTORJ. Ewe-M63 Hun/#41 '9 for 0. EAwar/ gala. femur? 2Z4 A flomezi March 11, 1952 E: G. HUMPAL EI'AL 9 3 JIB CRANE Filed May 19, 1949 3Sheets-Sheet 3 Patented Mar. 1 1, 1952 JIB CRANE Eugene G. Humpal andRoy 0. Balogh, Cleveland, Ohio, assignors, by mesne assignments, toMcCabe-Powers Auto Body 00., St. Louis, Mo., a corporation of MissouriApplication May 19, 1949, Serial No. 94,144

2 Claims. (01. 212 35) This invention relates to a hydraulicallyoperated jib crane having a rotatable vertical supporting post,load-liftin mechanism carried by the post, and a piston and cylindercouple, one member of which is connected to the post near its lower endand the other member of which operates the load-lifting mechanism. Oneof the objects of the invention is to provide such a crane with areadily operable mechanism for turning the post on its axis to swing theliftin mechanism laterally throughout a large range of movement. Anotherobject is to provide simple means for conveying pressure fluid between astationary conduit and the cylinder irrespective of the position thecylinder may be given by the turning of the crane. Another object of theinvention is to provide a simple and effective control for the pressurefluid to raise the lifting mechanism or lower it or hold it in anydesired position.

A preferred form of the invention is illustrated in the drawings and ishereinafter more fully explained.

In the drawings, Fig. 1 is a side elevation of our crane, the same beingshown as mounted on a suitable stationary support indicated in brokenlines; Fig. 2 is a fragmentary elevation at right angles to Fig. l, asindicated by the line 2-2 on Fig. 1, illustrating the manual turningmechanism and the controlling valve; Fig. 3 is a fragmentary plan, asindicated by the line 3--3 on Fig. 2, of the controlling valve; Fig. 4is a vertical section through the portion of the crane concerned withmounting and turning the vertical post, the section being in offsetplanes, as indicated by the line 4-4 on Fig. 2; Fig. 5 is an elevationpartly sectional of the parts shown in Fig. 4 in planes at right anglesto Fig. 4, as indicated by the offset line 5--5 on Fig. 4; Fig. 6 is adiagram in the nature of a plan (indicated by the line 66 on Fig. 1)illustrating the wide sweep of the crane; Fig. 7 is a diagramillustrating the arrangement of tank, pump, valves and conduits, forhydraulically operating the boom arm of the crane; Figs. 8, 9 and 10 arediagrams showing the condition with the valves respectively in neutralposition for holding the load, in position for raispivotally connectedat the lower end to the lower portion of the rotating column 30 and atthe 40. Suitable mechanism to be described turns the column 30 about itsaxis within the tubular support 20, while, irrespective of the position,a stationarily mounted controlling valve and suitable conduits leadingtherefrom supply fluid under pressure to the cylinder 50 to operate theboom.

Referring first to the stationary tubular member 20, this member isrigidly supported in a vertical position by any suitable frame Ill. Themember 20 is a cylindrical tube. It is surrounded near its upper end bya plate 2| which is welded to it and which is shown as secured by boltsl2 to a top member H of the frame. At the lower end of the tube 2|] is atransverse plate 22 welded to the tube. This plate is also welded to apair of vertical plates 23 which are welded to opposite sides of thetube 20. The plates 23 are welded to a plate 28, providing means wherebythey may be secured as by bolts I3 to a suitable vertical portion of theframe as, for instance, the channel-shaped bracket or beam i4, Fig. I.

The stationary cylinder 20, as will be seen, is

very rigidly held in vertical position in the frame and forms anefiective support for the rotatable column mounted in the cylinder. Toprovide suit able bearings for the column, as well as to reinforce thetube 20, we mount in this tube two bushings 24 and 25. The bushing 24 isshown as having an outward flange at its upper end which rests on thetop surface of the tube 20. The bushing 25 rests on the transverse plate22. g

The rotatable post or column 30, preferably comprises a cylindrical tube3| extending throughout the length of the column and a, reinforcing tube32 snugly embracing an intermediate portion of the through tube andfixedly secured thereto, as by welding at the ends of the reinforcingtube. The reinforcing tube 32 has its bearing in the bushing 24 andcarries a welded collar 34 resting on the upper end of the bushing.

As the bushing rests on the top of the tube 20, the

bracket or the boom is bifurcated and where they overlap a pin 36provides the pivotal connection. Near its lower end the reinforcingportion 32 of the column carries a radially extending ear 31 which isembraced by a bifurcated car 53 on the lower end of the cylinder 50, thetwo ears being pivotally connected by a transverse pin 54. A suitablepiston 55 within the cylinder is secured on the lower end of the pistonrod 5|. The upper end of this rod is pivoted at 51 to an intermediateregion of the boom.

The lower end of the cylinder 50 is connected by a flexible conduit 10and a coupling II with a conduit I2 in the interior of the rotatablecolumn. This latter conduit is swivelly connected, as later described,to a stationary conduit under the control of the control valve 60. Thisconstruction therefore enables pressure fluid to be supplied to thecylinder irrespective of the position it may occupy.

To turn the column about its axis to cause the boom 'to project in anydirection desired we provide a head 60 rigidly carried by the rotatablecolumn at its lower end and itself rigidly carrying a worm wheel 8|.Meshing with this worm wheel is a worm 90 on a horizontal shaft 9I towhich is coupled an extension shaft 92 suitably supported in the frameand carrying at its end a non -circular socket 93, Fig. 2. A removablecrank 95 is provided which has a noncircular stud 96 adapted tonon-rotatably enter the socket 93. Accordingly, this crank furnishesready means for rotating the worm and thereby the Worm wheel and thusturning the column with its boom and piston-and-cylinder couple aboutthe axis of the column.

The worm wheel BI with an extended hub 82 is shown in Fig. 4 as snuglysurrounding a central tubular extension 83 of the head 80 and as'lockedto said extension by a key 84. The worm Wheel is clamped axially inposition against a washer 85 bearing against the head 60 by a nut 86screwing onto the head extension 83. The nut is preferably notched andlocked by a latch 8'! in adjusted position. This construction enablesthe worm wheel to be readily mounted in place and effectively held inposition.

The cylindrical central portion 83 of the column head 80 has a bore Iextending almost to the bottom of the extension but closed at thebottom. The upper end of the bore is coupled at I to the conduit I2within the column, which as heretofore explained leads to the cylinder50. At the lower end of the passageway I00 is a lateral passagewayterminating in annular groove IOI. A stationary sleeve I02 surrounds thegroove WI and extends above and below it, where suitable packing as, forinstance, a pair of 0- rings I 04, I05 prevent leakage of fluid. Astationary conduit TI is coupled to the sleeve I02 and communicatesthrough a radial passage therein with the groove IOI. This conduit 11communicates externally, in a manner to be later described, with thevalve-controlled means for supplying fluid under pressure.

It results from the above construction that fluid under pressuresupplied to the conduit I1 passes to the axial passageway I00irrespective of the position of the column and thence passes to thecylinder 50. Accordingly, the fluid admitted may operate the cylinder inall positions of the column and whether the column is stationary or isin the act of being turned by the worm and, worm wheel mechanismmentioned. We provide a housing for the worm and worm abut and besecured to the plate 22.

wheel mechanism and the swiveled connection from the supply conduit,which may contain proper lubricating material. This housing comprises atubular section H0 which may align with the stationary tube 20 and atits upper end This tubular portion H0 is open at the worm, which latteris boxed-in by plane portions III, IIZ welded to the sleeve-like portionI I0. The sleeve IIO has an open bottom .to allow access to theconstruction ,within the housing. Normally, however, such bottom isclosed by a circular plate II5 within the housing supported by suitableradial pins IIB. Withdrawal of the pins enables the removal of the plateto allow access to the interior. A suitable nipple I I1 controlling apassageway through the sleeve I It provides for the insertion oflubricant.

The controlling valve 60 as heretofore stated is carried by an anglebeam portion I4 of the frame. The valve itself comprises a movablemember within a suitable casing 60 secured to the frame member I4 and tothe plate 28 by bolts I3. This casing 60 is hollow and its interior isconnected by a conduit 6I with a supply of fluid under pressure from asuitable pump. Within the valve casing 60 is a specially formed multi-.piston valve member 62 axially shiftable and.

having a shank extension 63 projecting beyond the casing and connectedto an operating member. The'operating member is shown in Fig. 3 as abent lever 65 intermediately pivoted at 66 to a stationary bracket andhaving its other end pivoted to the valve shank 63. .The full lineposition in Fig. 3 indicates the valve in its intermediate or holdingposition; a position of the lever forraising, and opposite extremeposition gar lgwering, are indicated by broken lines The multiple piston62 within the casing controls passageways to the pump, to the supplytank and to a pilot-operated check valve I20 from which the conduit Hleads through the swivel connection to the cylinder 50. Thepilot-operated check valve I20 is shown in Fig. 2. It has two tubularconnections. I2I and I22 with the control valve. Internally it is of theform indicated in Figs. '8, 9 and 10, wherein there is a valve seat I23on one side of which is a valve plug I 2.4 and on the other side apiston I25. A spring I25 tends to keep the valve plug onits seat. Thepiston, however, is provided with a rod adapted to extend through thevalve seat and abut the valve plug and when this piston is operated itmay unseat the valve.

The conduit I2I from the control valve 50 leads to the space between thepiston I25 and the valve plug I24 in the check valve, and the conduit I22 leads from the control valve to the space in the cylinder 52-0 behindthe piston I25.

The coupling of the controlling valve with the pump; the tank; thepilot-operated check valve, and the crane cylinder is indicated in Figs.'7 to 10. There I30 indicates the tank; I3I a line leading therefrom tothe pump; M a conduit leading from the pump to the control valve, andI32 and I33 lines from the control valve back to the tank. The tank I30is providedwith a suitable vent or breather I35 to prevent internalpressure.

The operation of the control valve piston and pilot-operated check valveWill be best understood from a subsequent description of the connectionsfor various conditions of operation in connection with the diagrams,Figs. 8, 9 and 10. It may be here noted, that it is possible by the meremanipulation of the lever 65 to admit pressure fluid to the lowerportion of the cylinder 50 to raise the boom and the load, or to holdsuch fluid as has been admitted in the cylinder and thereby hold theload stationary, or to release the fluid and allow gravity to bring downthe boom or any load carried thereby.

A more detailed description of the manually operated control valve andpilot-operated check valve will now be given for their differentpositions in Figs. 8, 9, 10. Fig. 8 shows the valves in a neutralposition, which is a holding position for the load. When the valvemember 62 is in the position shown in Fig. 8, the pump conduits BI areout of communication with either the conduit I 2| or I22 leading fromthe control valve. However, the pump conduits are in communication withconduit I33 leading to the tank. This allows the pump to operatecontinuously though idly. As the check valve I24 is held seated by itsspring I26, the fluid in the conduit 11 and in the lower portion of thecylinder holds the load in whatever position it may have.

To raise the load the control valve 62 is shifted by its lever 65 intothe position shown in Fig. 9. In this position one of the pump conduits6| is connected with the conduit I2I leading to the valve seat of thecheck valve. The pressure through the latter conduits unseats the valve,

against the action of its spring I26, so that the fluid is admitted tothe conduit 11 and passes to the cylinder, thus raising the load.

To lower the load the valve member 62 is shifted to the opposite end ofits casing. In this position, shown in Fig. 10, the conduit I22 isconnected with the pump. The result is that fluid under pressure isadmitted to the conduit I22 to act against the piston I25 of the checkvalve to overcome the action of the spring I26 and unseat the valve.This connects the conduit 11 from the cylinder with the return conduitI2I, so that the fluid may pass from the cylinder I20 back to thecontrol valve 62 and thence via the line I33 to the tank I30. The weightof the load forces the fluid in the cylinder in this direction, as theload lowers by gravity. When the lowering has reached the proper amount,the operation of the valve lever to shift the member 62 back to neutralposition stops the lowering operation and holds any load then suspendedon the hook.

Figs. 8, 9 and 10 indicate at I36 a pressure relief valve of the usualtype which is normally idle but may connect the conduit I2I with theconduit 133 back to the tank if the pressure is excessive. This preventsthe crane being operated to pick up a heavier load than that for whichit is intended.

It will be understood from the description given that we have provided ajib crane wherein the boom may be effectively operated and controlled byhydraulic pressure under the control of a convenient hand lever. Thesupporting post and hence the entire crane may be swung about the axisof the post to any extent desired by merely applying the hand crank tothe worm wheel mechanism. The control valve with its manual lever, andthe socket for receiving the hand crank, are preferably located in closeproximity with each other as indicated in Fig. 2, so that one operatormay readily effect all the controls and operations from a singleposition. Reference is made to our copending application,

Serial No. 169,586 filed June 22, 1950, which is directed to a, relatedjib crane apparatus.

We claim:

1. In a jib crane, the combination of a stationary upright tubularsupport, a tubular post rotatably mounted in the support, a boom pivotedto the upper end of the post, a cylinder pivoted to a lower portion ofthe post, a piston in the cylinder having a rod pivoted to the boom,said post having a hollow cylinder extension provided across its bottomend with a transverse wall, a

rod-like extension projecting co-axially downwardly from. the transversewall and being provided on its peripheral face adjacent its lower endwith an annular groove, said rod-like extension further being providedinternally with a closed-bottomed axial bore provided adjacent its lowerend with a radial orifice communicating with the annular groove, aconduit connecting the cylinder with the axial bore of the rod-likeextension, a ring surrounding the rod-like extension having a peripheralgroove on its interior face, said groove matching with and opening intothe annular groove, a supply conduit connected to the ring andcommunicating with the peripheral groove thereof, a worm wheel mountedon the downward extension of the post, and a worm meshing with the wormwheel for turning the post.

2. In a jib crane, the combination of a stationary upright tubularsupport, a tubular post rotatably mounted in the support, a boom pivotedto the upper end of the post, a cylinder pivoted to a lower portion ofthe post, a piston in the cylinder having a rod pivoted to the boom,said post having a hollow cylinder extension provided across its bottomend with a transverse wall, a rod-like extension projecting co-axiallydownwardly from the transverse wall and being provided on itsperipheral'face adjacent its lower end with an annular groove, saidrod-like extension further being provided internally with aclosed-bottomed axial bore provided adjacent its lower end with a radialorifice communicating with the annular groove, a conduit connecting thecylinder with the axial bore of the rod-like extension, a ringsurrounding the rod-like extension having a peripheral groove on itsinterior face, said groove matching with and opening into the annulargroove, a supply conduit connected to the ring and communicating withthe peripheral groove thereof, a worm wheel mounted on the downwardextension of the post, packing rings operatively disposed between therod-like extension and the ring above and below said matching grooves,and a worm meshing with the worm wheel for turning the post.

EUGENE G. HUMPAL. ROY O. BALOGH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 290,074 Le Duke Dec. 11, 18831,021,585 Ewert Mar. 26, 1912 2,374,045 Soucia Apr. 17, 1945 2,389,872Ruger et al. Nov. 27, 1945 2,437,466 Hail Mar. 9, 1948 2,446,488 PierceAug. 8, 1948

